Biased Reasoning

Abstract

The authors write, “Nevertheless, its clinical application is limited by the necessity for vascular surgery involving the carotid artery with the patient under general anesthesia, the need for frequent replacement of the subcutaneously implanted device, and the risk of infection entailed by device implantation” and go on to rate this treatment as a purely experimental approach for a high-risk population. In contrast, renal denervation is valued as a procedure “with a low complication rate.” I find the unstated implications of this description somewhat biased. The short duration of follow-up in the Symplicity trial, involving only 17 of the original 138 patients after two years, is not discussed. In nephrology practice at least, the need to use a contrast substance for RND is a considerable obstacle in cases of stage 3 and above chronic kidney disease (CKD). On the other hand, the complication rates of the latest baroreflex studies (Bisognano J et al., Am Coll Cardiol 2011) are considerably lower than those of the initial study and will probably fall even further in the ongoing BAT study as a result of unilateral implantation (XR-1). It seems necessary to indicate the varying indication and effect profiles that are emerging in this regard. Baroreceptor stimulation probably achieves a greater drop in blood pressure but requires (minor) surgery and replacement, like cardiac pacemakers, which are becoming rarer as technology progresses. RND requires the use of contrast substance, which entails risk. It is faster and cheaper to perform, but its long-term effect requires better evaluation.